Global WASH-Related Diseases and Contaminants

Waterborne Diseases

Waterborne diseases are caused by pathogenic microbes that can be directly spread through contaminated water. Most waterborne diseases cause diarrheal illness [Note: not all diseases listed below cause diarrhea]. Eighty-eight percent of diarrhea cases worldwide are linked to unsafe water, inadequate sanitation or insufficient hygiene (1) . These cases result in 1.5 million deaths each year, mostly in young children (1). The usual cause of death is dehydration. Most cases of diarrheal illness and death occur in developing countries because of unsafe water, poor sanitation, and insufficient hygiene. Other waterborne diseases do not cause diarrhea; instead these diseases can cause malnutrition, skin infections, and organ damage.

Sanitation & Hygiene-Related Diseases

Sanitation and hygiene are critical to health, survival, and development. A significant amount of disease could be prevented through better access to adequate sanitation facilities and better hygiene practices. Improved sanitation facilities (e.g., toilets and latrines) allow people to dispose of their waste appropriately, which helps break the infection cycle of many diseases.

Hygiene refers to acts that can lead to good health and cleanliness, such as frequent handwashing, face washing, and bathing with soap and clean water. Practicing personal hygiene in many parts of the world can be difficult due to lack of clean water and soap.

Providing access to safe water and sanitation facilities, and promoting proper hygiene behavior are important in reducing the burden of disease from sanitation and hygiene-related diseases.

Note: Many of the waterborne diseases of the previous section may also be associated with inadequate sanitation and hygiene.

Vector or Insect-borne Diseases Associated with Water

Water plays a critical role in the spread of insect-borne diseases because many insects, such as mosquitos, breed around water. An increase in water, especially from flooding, can directly impact the number of mosquitoes and other insects that breed around water, potentially creating high-risk environments for disease. Infected insects can transmit deadly disease to humans through their bite, such as malaria, dengue fever, and West Nile encephalitis. Worldwide, over one million people die each year due to mosquito-borne diseases, most of them young children in sub-Saharan Africa (2). Insect-borne diseases are rarely contracted in North America, but some have become more common recently, such as West Nile virus.

For more information on how to protect yourself from mosquitoes, ticks, fleas, and other insects, visit CDC's Travelers' Health webpage at: http://www.cdc.gov/travel/contentMosquitoTick.aspx

Neglected Tropical Diseases

Worldwide, approximately 1 billion people are affected by one or more neglected tropical diseases (NTDs) (3). According to the World Health Organization, the diseases below are named neglected because they "persist exclusively in the poorest and the most marginalized communities, and have been largely eliminated and thus forgotten in wealthier places" (4). Neglected tropical diseases are most often found in places with unsafe drinking water, poor sanitation and insufficient hygiene practices. These diseases can cause severe pain, disabilities, and death. Please note the diseases with double asterisks (**), are those NTDs that are directly water and/or hygiene-related.

* According to the World Health Organization, Buruli Ulcer is believed to be present within aquatic environments (e.g., small aquatic animals, biofilms) from where it can be spread to humans by an unknown mechanism.

** Neglected Tropical Diseases that are directly water and/or hygiene-related.